Piezoelectric properties of MnO2 doped low temperature sintering Pb(Mn1/3Nb2/3)O3–Pb(Ni1/3Nb2/3)O3–Pb(Zr0.50Ti0.50)O3 ceramics

In this study, in order to develop the composition ceramics for low loss and low temperature sintering multilayer piezoelectric actuator, Pb(Mn_1/3Nb_2/3)O₃–Pb(Ni_1/3Nb_2/3)O₃–Pb(Zr_0.50Ti_0.50)O₃ (abbreviated as PMN-PNN-PZT) ceramics were fabricated using Li₂CO₃ and Na₂CO₃ as sintering aids, and their piezoelectric and dielectric characteristics were investigated according to the amount of MnO₂ addition. At the 0.2 wt% MnO₂ doped specimen sintered at 900 °C, density and mechanical quality factor (Q _m) showed the maximum values of 7.81[g/cm³]and 1186, respectively. And also, at 0.1 wt% MnO₂ doped specimen, electromechanical coupling factor (k _p), piezoelectric constant (d ₃₃) of specimen showed the maximum values of 0.608 and 377[pC/N], respectively. Dielectric constant (? _r) slightly decreased with increasing MnO₂. Taking into consideration the density of 7.81[g/cm³], electromechanical coupling factor (k _p)of 0.597 the mechanical quality factor (Q _m) of 1,186, and piezoelectric constant (d ₃₃) of 356[pC/N], it could be concluded that 0.2 wt% MnO₂ doped composition ceramics sintered at 900 °C was best for low loss and low temperature sintering multilayer piezoelectric actuator application.     

Piezoelectric and dielectric properties of low temperature sintering Pb(Mn1/3Nb2/3)O3–Pb(Zn1/3Nb2/3)O3–Pb(Zr0.48Ti0.52)O3 ceramics with variation of sintering time

Pb(Mn_1/3Nb_2/3)O₃–Pb(Zn_1/3Nb_2/3)O₃–Pb(Zr_0.48Ti_0.52)O₃ (abbreviated as PMN–PZN–PZT) ceramics containing Li₂CO₃, Bi₂O₃ and CuO as sintering aids were fabricated using two-stage calcinations method in order to develop low temperature sintering ceramics for multilayer piezoelectric actuators. Their dielectric and piezoelectric properties were investigated according to the variation of sintering time. All the specimens sintered at 930°C for 60~150 min showed tetragonal phases without secondary phases. Electromechanical coupling factor (kp), dielectric constant (ε _r) and piezoelectric constant (d ₃₃) increased with the increase of the sintering time. The mechanical quality factor (Qm) exhibited maximum of 1,815 with the increase of sintering time for 120 min and then slightly decreased. At the sintering temperature of 930°C and the sintering time of 120 min, the optimal values such as the density of 7.69 g/cm³, kp of 0.516, ε _r of 1158, Qm of 1815, and d ₃₃ of 287 pC/N were found for multilayer piezoelectric actuators.     

Piezoelectric and dielectric characteristics of low-temperature-sintering Pb(Mg1/2W1/2)O3–Pb(Ni1/3Nb2/3)O3–Pb(Zr,Ti)O3 ceramics according to the amount of PNN substitution

In this study, in order to develop low-temperature-sintering ceramics for multilayer piezoelectric actuator, Pb(Mg_1/2W_1/2)O₃–Pb(Ni_1/3Nb_2/3)O₃–Pb(Zr,Ti)O₃ (abbreviated as PMW–PNN–PZT) ceramics were fabricated using Li₂CO₃ and CaCO₃ as sintering aids and their dielectric and piezoelectric properties were investigated with the amount of Pb(Ni_1/3Nb_2/3)O₃ (abbreviated as PNN) substitution. PMW–PNN–PZT composition ceramics could be sintered up to 870°C by adding sintering aids. At the sintering temperature of 900°C, electromechanical coupling factor (k _p), piezoelectric constant (d ₃₃) and Curie temperature (Tc) in the composition ceramics with 9 ;mol% PNN substitution showed the optimal value of 0.64 517 ;pC/N and 317°C, respectively for multilayer actuator application.     

Piezoelectric and Dielectric Properties of Pb(Zr x Ti1 − x )O3-Pb(Ni1/3Sb1/3Nb1/3)O3 Piezoelectric Ceramics

In this paper, piezoelectric and dielectric properties of 0.9PbZr_xTi_1–xO₃-0.1PbNi_1/3Sb_1/3Nb_1/3O₃ were studied as a function of Zr/Ti mole ratio(x) for application to piezoelectric actuator. Also, microstructure and crystalline phase are investigated by using SEM and XRD, respectively. As a results, the substitution of Sb5+ to B-site increases the piezoelectric and dielectric properties, and when Zr/Ti mole ratio is 49/51 and ternary mole ration is 0.1(0.9PbZr_0.49Ti_0.51O₃-0.1PbNi_1/3Sb_1/3Nb_1/3O₃), the corresponding composition were found belonging to the Morphotropic Phase Boundary region with electromechanical coupling coefficient(k_p), mechanical quality factor (Q_m), permittivity(_r) and piezoelectric strain constant(d₃₃) equaled to 63%, 360, 2000 and 470 pC/N, respectively. Sintering temperature was about 1150_C and Curie temperature was determined around 290_C.     

Dielectric and pyroelectric properties of Li2CO3 doped 0.2Pb(Mg1/3Nb2/3)O3–0.5Pb(Zr0.48Ti0.52)O3–0.3Pb(Fe1/3Nb2/3)O3 ceramics

Relaxor ferroelectric compositions of 0.2Pb(Mg_1/3Nb_2/3)O₃–0.5Pb(Zr_0.48Ti_0.52)O₃–0.3Pb(Fe_1/3Nb_2/3)O₃ (0.2PMN–0.5PZT–0.3PFN) ceramics were doped with different concentrations of Li₂CO₃ and were prepared by a columbite precursor process. Their structural, dielectric and pyroelectric properties were studied. A phase analysis was performed using the X-ray diffraction patterns from 2θ?=?44° to 46°, over which the tetragonal phase displays two peaks, (002)_T and (200)_T, while the rhombohedral phase displays one peak, (200)_R. A well saturated P–E hysteresis loop was obtained for the 0.2PMN–0.5PZT–0.3PFN ceramic doped with 0.2 wt.% Li₂CO₃, and the values for the remnant polarization (P _r) and coercive field (E _c) were 30 μC/cm² and 5.4 kV/cm, respectively. A maximum value of the pyroelectric coefficient, 518 μC/m²K, was obtained for the 0.2PMN–0.5PZT–0.3PFN ceramic doped with 0.3 wt.% Li₂CO₃ at the maximum temperature (T _max) due to the decrease of the binding energy for the polarization charge which in formed at the surface.     

DIELECTRIC AND PIEZOELECTRIC CHARACTERISTICS OF 0.07Pb (Mn1/3Nb2/3) O3 −0.10Pb (Ni1/3Nb2/3) O3− 0.83Pb(Zr0.48Ti0.52) O3 CERAMICS ACCORDING TO THE HEATING RATE

ABSTRACT

In this study, in order to develop the composition ceramics for low loss multilayer piezoelectric actuator, 0.07Pb (Mn_1/3Nb_2/3) O₃ ?0.10Pb (Ni_1/3Nb_2/3) O₃? 0.83Pb(Zr_0.48Ti_0.52) O₃ (abbreviated as PMN-PNN-PZT) ceramics were fabricated using Li₂CO₃, Bi₂O₃ and CuO as sintering aids and according to variation of heating rate. And also, their dielectric and piezoelectric properties were investigated. At the heating rate of 700°C/h and sintering temperature of 900°C, density, electromechanical coupling coefficient (kp), mechanical quality factor (Qm), dielectric constant (ε _r ) and piezoelectric constant (d₃₃) of PMN-PNN-PZT ceramics showed the excellent values of 7.67 g/cm³, 0.58, 1199, 1560 and 380 pC/N, respectively for low loss multilayer piezoelectric actuator application.     

Synthesis and characterizations of the (1 − x)Pb(Sc1/2Nb1/2)O3–xPbTiO3 solid solution ceramics

We report a systematic study of the (1???x)Pb(Sc_1/2Nb_1/2)O₃–xPbTiO₃ (PSN–PT) solid solution in the form of ceramics with compositions at or near the morphotropic phase boundary (MPB) region (0.35?≤?x?≤?0.50). The PSN–PT ceramics have been synthesized by an improved two-step wolframite precursor method. The synthetic process has been optimized in terms of calcining and sintering conditions. Both dielectric permittivity measurements and differential scanning calorimetry (DSC) show a clear peak at T _C, at which the transition from the paraelectric to ferroelectric phase takes place. Interestingly, the solid solution of the MPB compositions displays a T _C?>?200 °C, i.e. higher than the T _C of the Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃ and Pb(Zn_1/3Nb_2/3)O₃–PbTiO₃ solid solutions, making the PSN–PT system very promising piezoelectric and ferroelectric materials for high-temperature applications. A dielectric maximum as high as 50,000 is obtained for the 0.65PSN–0.35PT ceramic with losses smaller than 0.05. The values of the remnant polarization and the strain level of the PSN–PT ceramics are comparable to those of the PZT ceramics.     

Study of the electrical properties of Pb(Zn,Ni)1/3Nb2/3O3–PbTiO3 ceramics across the morphotropic phase boundary

Structure and electrical properties of (1???x)Pb(Zn_0.2Ni_0.8)_1/3Nb_2/3O₃–xPbTiO₃ ceramics with x?=?0.24–0.38 were examined in detail. X-ray diffraction measurements reveal that all samples are in pure perovskite phase, and most of them lie within the morphotropic phase boundary (MPB) region. The dielectric behaviors of all compositions are characterized with diffuse phase transition and frequency dispersion. The variable power law and the Vogel–Fulcher relation have been used to describe such dielectric behaviors. The highest dielectric constant and the largest piezoelectric coefficient are simultaneously observed when x?=?0.30. The variation of the ferroelectric property with PT content is also discussed.     

Effect of CuO addition on sintering temperature and piezoelectric properties of 0.05Pb(Al0.5Nb0.5)O3−0.95Pb(Zr0.52Ti0.48)O3+0.7 wt.% Nb2O5 + 0.5 wt.% MnO2 ceramics

Effect of CuO addition on piezoelectric properties of 0.05Pb(Al_0.5Nb_0.5)O₃?0.95Pb(Zr_0.52Ti_0.48)O₃+0.7 wt.% Nb₂O₅ + 0.5 wt.% MnO₂ (PAN-PZT) ceramics was studied to decrease the sintering temperature below 900°C for LTCC. The PAN-PZT ceramics sintered at 1200°C had piezoelectric properties of d ₃₃ = 340 pC/N, k _p = 61.6%, Q _m = 1,725, and density of 7.5 g/cm³. The addition of CuO significantly decreased the sintering temperature due to the formation of liquid phase containing a binary combination of PbO and CuO in grain boundary. Piezoelectric properties of d ₃₃ = 361 pC/N, k _p = 57%, Q _m = 145, and density of 7.8 g/cm³ were achieved at sintering temperature of 900°C. The CuO doped PAN-PZT ceramics show high density and d ₃₃ at low sintering temperature though its electromechanical quality factor abruptly decreases due to the CuO additive effect.     

Piezoelectric properties of the high temperature MPB xPbTiO3 - (1−x)[BiScO3 + Bi(Ni1/2Ti1/2)O3] composition

The ternary perovskite xPbTiO₃ - (1?x)[BiScO₃ + Bi(Ni_1/2Ti_1/2)O₃] (PT-BS-BNiT), where x?=?0.54 is the morphotropic phase boundary composition, was studied for high temperature ferroelectric applications. Polycrystalline ceramics were prepared using the standard solid-state methods. The stoichiometric ceramic was found to have room temperature dielectric permittivity and loss values at 1 kHz of 1490 and 0.049 respectively. Piezoelectric properties, of the stoichiometric composition, measured included: P_r?=?31.0 μC/cm², E_c?=?25.0 kV/cm, d₃₃?=?340 pC/N, d₃₃ ^*?=?896 pm/V, and a bipolar electromechanical strain of 0.25 %. From these data, the Curie temperature was T_C?=?370 °C and the depoling temperature was T_D?=?325 °C. Processing ceramics with excess bismuth improved the low field piezoelectric coefficients with a maximum of d33?=?445 pC/N, while increasing the lead content increased the transition temperatures. The depoling and Curie temperatures of all compositions were measured to be between 275 and 400 °C.     

Properties of (001)-textured Pb(Mg1/3Nb2/3)O3–PbTiO3 thin films

Relaxor ferroelectric Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃ (PMN–PT) thin films with [001] preferential orientation were deposited on platinized silicon wafers by a sol–gel method, in which a PbO seeding layer was involved. The influences of annealing temperature on the crystal phase, microstructure, and electrical properties of the PMN–PT films were investigated. Pyrochlore-free perovskite PMN–PT films could be formed on PbO-seeded Pt(111)/Ti/SiO₂/Si wafers at 800 °C, which was also the optimal annealing temperature for endowing the film with the best ferroelectric and dielectric properties. The enhanced properties were attributed to the improved crystallinity and microstructure. The leakage behaviors of the PMN–PT films annealed at different temperatures were also measured and discussed.     

Effect of additive SrWO4 on microwave dielectric properties of SrTiO3–Sr(Mg1/3Nb2/3)O3 ceramics

The crystal structure and the properties of a new microwave dielectric ceramics x SrTiO₃–(1???x)Sr(Mg_1/3Nb_2/3)O₃ have been investigated. With x?=?0.025, The new microwave dielectric ceramic achieves the dielectric properties of a dielectric constant ? _r ～27.8, a Q?×?f value ～26,800, and a τ _f value ～7.4 ppm/°C. When the SrWO₄ is added, the sintering temperature of x SrTiO₃–(1???x)Sr(Mg_1/3Nb_2/3)O₃ ceramics will fall to 1350 °C, and its Q?×?f value can be improved further and the τ _f value becomes smaller. When the SrWO₄ is added by 0.07 mol, the specimen acquires the following microwave properties: a dielectric constant ? _r ～30.3, a Q?×?f value ～29,500, and a τ _f value of approximately ?0.4 ppm/°C.     

Pb(Mg1/3Nb2/3)O3 and (1 − x)Pb(Mg1/3Nb2/3)O3 − xPbTiO3 Relaxor Ferroelectric Thick Films: Processing and Electrical Characterization

The lead magnesium niobate [Pb(Mg_1/3Nb_2/3)O₃ or PMN], and its solid solutions with lead titanate (PbTiO₃ or PT), are of great interest because of their high electromechanical properties. At large PMN content, these materials exhibit relaxor characteristics with large electrostrictive strains and a large permittivity, while compositions near the morphotropic phase boundary present very interesting piezoelectric properties. So far, properties of these materials in ceramic, thin film and single-crystal form have been investigated. In this paper, we report on preparation and properties of pyrochlore free PMN and 0.65PMN-0.35PT thick films (thickness = 10 to 20 m). The films were prepared from ethyl cellulose ink by screen printing on alumina substrate. The influence of various parameters, such as powder characteristics, inks formulation and films sintering conditions, on films densification are discussed. The dielectric and electromechanical properties of the films were examined. Relaxor-like behaviour was clearly demonstrated in PMN films. The maximum relative permittivity for PMN film was 10000 (at 0.1 kHz), which is lower than in bulk ceramics (17800 at 0.1 kHz) prepared under the same conditions. For 0.65PMN-0.35PT, the maximum relative permittivity was around 15500 against 24000 in the bulk. Several parameters, which might be responsible for the lower permittivity, are discussed. Poled 0.65PMN-0.35PT thick films exhibit relatively large piezoelectric response (d ₃₃ up to 200 pm/V) and unipolar strains approaching 0.1%, making these films of interest for various actuator and transducer applications.     

Structural evolution and microwave dielectric properties of (1 − x)BaZn1/3Nb2/3O3 + xBaMg1/2W1/2O3 ceramics

Structural evolution and microwave dielectric properties of (1 − x)BaZn_1/3Nb_2/3O₃ + xBaMg_1/2W_1/2O₃ (0 ≤ x ≤ 1) system have been investigated in this work. All samples exhibit single perovskite phase except for the samples with x = 0 and x ≥ 0.8 in which barium niobate and BaWO₄ second phase existed, respectively. 1:1 cations ordering existed in the samples with x ≥ 0.1, and the ordering degree increases with the increase of x. Liquid phase sintering was observed in the sample with x ≥ 0.8. Dielectric constant decreases almost linearly from 40.8 to 17.4 with increasing x. Q × f value monotonically increases from 26,162 GHz to 64,705 GHz with increasing x. The τ_f value changes from +30 ppm/°C to −27.8ppm/°C. Near zero τ_f value of −1.4 ppm/°C could be obtained at x = 0.4 composition.     

Synthesis of (Ba0.5Sr0.5)(Ti1 − x Zr x )O3 ceramics: Effect of Zr content on room temperature electrical properties

The phase formation behavior and room temperature dielectric properties of bulk perovskite solid solution composition (Ba_0.5Sr_0.5)(Ti_1 − x Zr _x )O₃ have been investigated. The samples with different Zr-content were prepared through solid state reaction. The XRD investigation showed that Zr⁺⁴ is systematically dissolved in Ba_0.5Sr_0.5TiO₃ lattice up to about 60 atm.% substitution, having cubic Pm3m structure. Eighty atom percent Zr substituted composition showed to contain a cubic phase similar to that of x = 0.6 composition and a tetragonal (I4/mcm) phase. That is the solid solution breaks around at 80 atm.% Zr substitutions. Ba_0.5Sr_0.5ZrO₃ was having orthorhombic Imma structure. Decrease in grain sizes were observed with increase in Zr content. The permittivity of the ceramics decreased with the increase in Zr substitution. The frequency dependency of dielectric loss in the frequency range 10 Hz to 10 MHz, were improved with Zr substitution in the ceramics. The room temperature ac and dc conductivity also decreased significantly with the increase in Zr-content.     

Effect of Zr/Ti ratio on electrically induced light scattering property of Pb0.92La0.08 (ZryTi1−y)0.98 O3 ceramics

Journal of Electroceramics - A series of double-perovskite oxides Sr2Sr1-xCaxTeO6 (0?≤?x?≤?1) samples have been prepared in order to study the effect of...     

Li:(Ni+Co+Mn)对Lix Ni1/3Co1/3Mn1/3O2性能的影响

以共沉淀氢氧化物为前驱体制备了层状LixNi1/3Co1/3Mn1/3O2(x＞1)正极材料,并采用X射线衍射光谱法(XRD)、扫描电子显微镜(SEM)、充放电测试表征了其结构与性能.研究了不同的Li与M摩尔比对材料性能的影响.结果表明:随着Li与M摩尔比的升高,样品显示电化学性能提高,尤其是循环性能和倍率性能.当Li与M摩尔比大于1.20时放电容量开始下降.Li与M摩尔比为1.20的试样在截止电压为2.75～4.4 V范围里首次放电比容量达到160.5 mAh/g.     

Investigation of dielectric and relaxor ferroelectric properties in Ba(Zr x Ti1−x )O3 ceramics

Barium zirconate titanate Ba(Zr _x Ti_1?x )O₃ (BZT x?=?0.1, 0.15, 0.2, 0.25) ceramics doped with Nb₂O₅ have been prepared by a traditional solid phase reaction. The temperature dependence of dielectric permittivity has been investigated. The results show that the phase transition temperature T _c is depressed and the diffuse phase transition behavior is enhanced with increasing Zr content. The Cole–Cole plot has been discussed and the cause of the deviation has been analyzed. The temperature dependence of inverse dielectric constants was investigated. A modified Curie–Weiss law can be used to describe the diffuseness of a phase transition, and diffusion factor increases with the Zr content.     

Synthesis and Dielectric Characterization of Pyrochlore-Free Pb1−x Ba x (Zn1/3Nb2/3)O3 Ceramics

The dielectric properties and synthesis of pyrochlore-free lead zinc niobate ceramics with Ba substituting for Pb were investigated. Ba partial substitution for Pb was effective in stabilizing the perovskite structure in PZN ceramics, where the minimum amount of Ba substitution needed was about 20 mol%. The dielectric loss and the temperature coefficient of dielectric constant of PZN were reduced markedly with Ba substitution, while the dielectric constant was greater than 110. Good dielectric properties were obtained for the composition of Pb_0.3Ba_0.7(Zn_1/3Nb_2/3)O₃: = 133.5, tan = 0.0009, = –811 ppm/°C.     

Li(Ni1/3Co1/3Mn1/3)O2正极材料的电化学性能

用共沉淀法制备出(Ni1/3Co1/3Mn1/3)(OH)2,与LiOH·H2O混合后,在900℃下焙烧12 h,得到锂离子电池正极材料Li(Ni1/3Co1/3Mn1/3)O2.在2.70～4.35 V,电流为40 mA/g时,循环性能稳定.当截止电压升高到4.60 V时,容量可达190 mAh/g.循环伏安实验表明,材料的结构在循环过程中保持稳定.